On Sun, 2005-02-27 at 16:07 +0100, Sven C. Koehler wrote: > Hello! > > I have two vectors and want to know how many of their elements are > equal - > what's the best way to do this in R? > > Best regards, > > Sven
> a <- 1:10 > b <- 8:20 > a [1] 1 2 3 4 5 6 7 8 9 10 > b [1] 8 9 10 11 12 13 14 15 16 17 18 19 20 If you just want to know how many elements in 'a' are in 'b': > sum(a %in% b) [1] 3 If you want to know which elements in 'a' are in 'b': > which(a %in% b) [1] 8 9 10 See ?"%in%" and ?which for more information. HTH, Marc Schwartz ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
